物体在外力作用下沿直线或弧线以中心位置（平衡位置）为基准的往复运动 ,称为机械振动 ,简称振动。物体离开中心位置的最大距离为振幅。单位时间内（Ｓ）内振动的次数称为频率 ,它是评价振动对人体健康影响的常用基本参数。振动对人体的影响分为全身振动和局部振动。全身振动 Object under the action of external force along the straight line or arc to the center position (balance position) as the base of the reciprocating motion, known as mechanical vibration, referred to as vibration. The maximum distance the object is from the center is the amplitude. The number of vibrations per unit time (S) is called frequency, which is a common basic parameter for evaluating the impact of vibration on human health. The impact of vibration on the human body is divided into systemic vibration and local vibration. Whole body vibration